Development of Laboratory Testing Protocol for Rapid-Setting Cementitious Material for Airfield Pavement Repairs

2012 ◽  
Vol 2290 (1) ◽  
pp. 89-98 ◽  
Author(s):  
Lucy P. Priddy ◽  
Timothy W. Rushing
Keyword(s):  
Air Force ◽  
Material Selection ◽  
Selection Process ◽  
Cementitious Materials ◽  
Test Methods ◽  
Portland Cement Concrete ◽  
Test Protocol ◽  
Premature Failure ◽  
Rapid Setting ◽  
Selection Protocol

Many commercial off-the-shelf products for repairing portland cement concrete (PCC) pavements provide short set times, high early strengths, and the durability to withstand aircraft traffic. Twenty-five rapid-setting cementitious materials were investigated through laboratory and field evaluations to determine their suitability for repairing critical PCC airfield pavements. Standard laboratory tests were performed to characterize the properties of the materials and provide a protocol for assessing their suitability for field repairs. Criteria for using rapid-setting cementitious materials for repairing airfield pavements were published in 2008 by the U.S. Air Force. The criteria, based on laboratory and full-scale testing, allowed users to reduce the risk of premature failure of repairs by omitting unacceptable materials from their list of potential repair materials. The American Society of Testing and Materials published a similar test protocol in 2009. On the basis of a comparison of these two certification procedures and knowledge gained through field experience, the Air Force selection protocol was further updated in 2010 to improve the material selection process. The laboratory test methods used to develop the selection protocol along with the results from the material investigations are discussed in this paper.

Evaluation of strength of concrete on different initial exposure condition

2020 ◽  
Vol 13 ◽  
Author(s):  
Sri Ram Krishna Mishra ◽  
Pradeep Kumar Ghosh ◽  
Manoj Kulshreshtha
Keyword(s):  
Portland Cement ◽  
High Strength ◽  
Cementitious Materials ◽  
General Purpose ◽  
Supplementary Cementitious Materials ◽  
Exposure Condition ◽  
Portland Cement Concrete ◽  
Initial Exposure ◽  
Skilled Manpower ◽  
Standard Practices

Background: The previous studies have focused curing effect of mainly on high strength concrete, where strict supervision is maintained. This study is based upon general purpose concreting work for commercial and residential construction in absence of skilled manpower and supervision. Objective: The objective of this study is to establish a thumb rule to provide 7 days initial curing for maintaining quality for unsupervised concreting irrelevant to type of cement and grading. Methods: In this study concrete samples made with locally available commercial cements were cured for various initial exposure. Results: The results shows that concrete cured after a gap of 4 days from the time of de-moulding have given lowest strength as compared to concrete cured in standard practices i.e. where proper curing protocol had been followed. Conclusion: Initial curing is most important aspect of gaining desired strength. The findings after this study shows that curing affects the strength of concrete in variable grading. Initial curing has great importance for concrete with all types of Portland cement. Concrete with supplementary cementitious materials gives lowest strength initially but results higher strength after 28 days as compared to Portland cement.

scholarly journals Laboratory Test to Evaluate the Resistance of Cementitious Materials to Biodeterioration in Sewer Network Conditions

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 686
Author(s):  
Amr Aboulela ◽  
Matthieu Peyre Lavigne ◽  
Amaury Buvignier ◽  
Marlène Fourré ◽  
Maud Schiettekatte ◽  
...  
Keyword(s):  
Calcium Aluminate ◽  
Standardized Test ◽  
Performance Indicator ◽  
Cementitious Materials ◽  
Test Method ◽  
Sustainable Construction ◽  
Public Health Issue ◽  
Sulfur Source ◽  
Test Protocol ◽  
Wide Range

The biodeterioration of cementitious materials in sewer networks has become a major economic, ecological, and public health issue. Establishing a suitable standardized test is essential if sustainable construction materials are to be developed and qualified for sewerage environments. Since purely chemical tests are proven to not be representative of the actual deterioration phenomena in real sewer conditions, a biological test–named the Biogenic Acid Concrete (BAC) test–was developed at the University of Toulouse to reproduce the biological reactions involved in the process of concrete biodeterioration in sewers. The test consists in trickling a solution containing a safe reduced sulfur source onto the surface of cementitious substrates previously covered with a high diversity microbial consortium. In these conditions, a sulfur-oxidizing metabolism naturally develops in the biofilm and leads to the production of biogenic sulfuric acid on the surface of the material. The representativeness of the test in terms of deterioration mechanisms has been validated in previous studies. A wide range of cementitious materials have been exposed to the biodeterioration test during half a decade. On the basis of this large database and the expertise gained, the purpose of this paper is (i) to propose a simple and robust performance criterion for the test (standardized leached calcium as a function of sulfate produced by the biofilm), and (ii) to demonstrate the repeatability, reproducibility, and discriminability of the test method. In only a 3-month period, the test was able to highlight the differences in the performances of common cement-based materials (CEM I, CEM III, and CEM V) and special calcium aluminate cement (CAC) binders with different nature of aggregates (natural silica and synthetic calcium aluminate). The proposed performance indicator (relative standardized leached calcium) allowed the materials to be classified according to their resistance to biogenic acid attack in sewer conditions. The repeatability of the test was confirmed using three different specimens of the same material within the same experiment and the reproducibility of the results was demonstrated by standardizing the results using a reference material from 5 different test campaigns. Furthermore, developing post-testing processing and calculation methods constituted a first step toward a standardized test protocol.

scholarly journals An Investigation of Geography and Climate Induced Distresses Patterns on Airfield Pavements at US Air Force Installations

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Lauren K. Sahagun ◽  
Moses Karakouzian ◽  
Alexander Paz ◽  
Hanns de la Fuente-Mella
Keyword(s):  
Air Force ◽  
Condition Index ◽  
Portland Cement Concrete ◽  
Climate Zones ◽  
Pavement Condition ◽  
Pavement Distress ◽  
Western Us ◽  
Us Air Force ◽  
Pavement Condition Index ◽  
Predominant Factor

This study investigated climate induced distresses patterns on airfield pavements at US Air Force installations. A literature review and surveys of Pavement Condition Index indicated that the predominant factor contributing to the development of pavement distress was climate. Results suggested that, within each type of pavement distress, a geographic pattern exists which is strongly correlated to conventional US climate zones. The US Air Force Roll-Up Database, housing over 50,000 records of pavement distress data, was distilled using a process designed to combine similar distresses while accounting for age and size of samples. The process reduced the data to a format that could be used to perform krig analysis and to develop pavement behavior models for runways built with asphalt cement (AC) and Portland cement concrete (PCC). Regression and krig analyses were conducted for each distress type to understand distress behavior among climate zones. Combined regression and krig analyses provided insight into the overall pavement behavior for AC and PCC runways and illustrated which climate zone was more susceptible to specific pavement distresses. Distress behavior tends to be more severe in the eastern US for AC and in the western US for PCC runway pavements, respectively.

Research on Material Selection with Multi-Attribute Decision Method and G1 Method

2014 ◽  
Vol 952 ◽  
pp. 20-24 ◽  
Author(s):  
Xue Jun Xie
Keyword(s):  
Material Selection ◽  
Selection Process ◽  
Selection Problem ◽  
Topsis Method ◽  
Attribute Weight ◽  
Multi Attribute Decision Making ◽  
Judgment Matrix ◽  
Optimal Material ◽  
Selection Of ◽  
Better Than

The selection of an optimal material is an important aspect of design for mechanical, electrical, thermal, chemical or other application. Many factors (attributes) need to be considered in material selection process, and thus material selection problem is a multi-attribute decision making (MADM) problem. This paper proposes a new MADM method for material selection problem. G1 method does not need to test consistency of the judgment matrix. Thus it is better than AHP. In this paper, firstly, we use the G1 method to determine the attribute weight. Then TOPSIS method is used to calculate the closeness of the candidate materials with respect positive solution. A practical material selection case is used to demonstrate the effectiveness and feasibility of the proposed method.

scholarly journals Sustainable Construction by Means of Improved Material Selection Process

2019 ◽  
Vol 3 (1) ◽  
pp. 85 ◽  
Author(s):  
Koorosh Gharehbaghi ◽  
Maged Georgy
Keyword(s):  
Energy Savings ◽  
Material Selection ◽  
Selection Process ◽  
Sustainable Construction ◽  
Construction Operation ◽  
Selection Factors ◽  
Strength And Durability ◽  
Operation Cost ◽  
Selection Of

Whilst sustainable construction relates to both a building’s structure and the use of proper life cycle processes, the selection of the most appropriate material/s is deemed a considerable undertaking. Throughout a building’s lifecycle that extends from design, construction, operation, maintenance, renovation, until demolition, the selection of sustainable material/s is a particularly crucial task for the development and establishment of such structures. Traditionally, there are three main materials for general construction: (1) Steel, (2) Concrete and (3) Timber. These materials not only influence the function within the structure, but also affect the operation cost and energy usage. Operation cost reduction and energy savings are typically elements of the sustainable construction sphere. However, in developing countries, there is a variety of highly critical factors, which can impact material selection as well as the long-term sustainability of the structure, including: Fire Performance, Environmental Impact, Structural Performance (strength and durability), and Functioning Capabilities. Accordingly, this paper will first compare the sustainability of these three key materials and then converse with appropriate processes for material selection. Attention will be given to the sustainable construction recompense associated with the different material selection factors. Doing so ensures a more sustainable built environment by means of an improved material selection process.

Evaluation of Test Protocol for Eutectic Die Attach Using High Power LEDs

2011 ◽  
Vol 2011 (1) ◽  
pp. 000136-000141 ◽  
Author(s):  
Amanda Hartnett ◽  
Seth Homer ◽  
Donald Beck ◽  
Daniel Evans
Keyword(s):  
High Power ◽  
Coefficient Of Thermal Expansion ◽  
Test Methods ◽  
Test Protocol ◽  
High Brightness ◽  
Light Emitting ◽  
Power Semiconductor ◽  
Heat System ◽  
Die Attach ◽  
Manufactured Products

High-power semiconductor devices, such as high-brightness Light Emitting Diodes (LEDs), must be mounted using a robust adhesive material to handle the temperature fluctuations generated by the chip and the mechanical stresses due to the coefficient of thermal expansion (CTE) mismatches between the die material and substrate it is mounted to. The selected material must also comply with current legislation restricting manufactured products containing numerous materials including some that were historically popular in HB LED applications due to environmental concerns. Eutectic gold-tin (AuSn) materials meet these requirements, and process recommendations for their implementation will be presented in this paper. Utilizing a Palomar Technologies die bonder, AuSn solder preforms and paste will be placed/dispensed and reflowed using a Pulsed Heat System (PHS). Evaluation methods comparing these means of eutectic die attach to a pre-plated AuSn die will be discussed. Technical generalizations will be detailed to explain the derivation of test methods as well as hypotheses of results.

scholarly journals Design Innovation and Validation of a Non-Electric Hearing Aid for Improved Usability

2018 ◽  
Vol 7 (3.7) ◽  
pp. 90
Author(s):  
Poh Kiat Ng ◽  
Kian Siong Jee ◽  
Li Wah Thong ◽  
Jian Ai Yeow
Keyword(s):  
Cost Analysis ◽  
Hearing Aids ◽  
Material Selection ◽  
Selection Process ◽  
Hearing Aid ◽  
Electric Hearing ◽  
Design Innovation

This study aims to innovate and validate the design of a non-electric hearing aid for improved usability. Studies on conventional and existing hearing aids were carried out before the actual study on developing this non-electric hearing aid was done. The final product underwent a series of evaluations in order to verify its viability and usability. Conceptualisation, material selections and concept selections were carried out in order to select the most appropriate concept for this study. The material selection process ensures that the choice of material is appropriate for the specific requirements of the components to be achieved. Subsequently, a detailed cost analysis was carried out to ensure that the manufactured product would be affordable to the customers. Several experiments and tests were performed to evaluate the product’s performance. Although a validated prototype for a non-electric hearing aid is in hand, future improvements on the fabricated product are still needed in order to ready the product for its future commercialisation phase. 

Structural Alloys

1983 ◽  
pp. 371-411 ◽  
Author(s):  
H. I. McHenry
Keyword(s):  
Aluminum Alloys ◽  
Physical Properties ◽  
Stainless Steels ◽  
Material Selection ◽  
Selection Process ◽  
Austenitic Stainless Steels ◽  
General Information ◽  
Metals And Alloys ◽  
Mechanical And Physical Properties ◽  
Cryogenic Application

Abstract This chapter discusses the structural alloys being used for cryogenic applications in commercially significant quantities. It emphasizes the practical considerations involved in the material selection process and provides the information necessary to make preliminary selections of alloys most suitable for the intended cryogenic application. The chapter provides general information on a class or group of alloys, their representative mechanical and physical properties, and their fabrication characteristics. The materials covered are austenitic stainless steels, nickel steels, aluminum alloys, and other metals and alloys.

scholarly journals Thermoplastic Matrix Material Selection Using Multi Criteria Decision Making Method for Hybrid Polymer Composites

2014 ◽  
Vol 564 ◽  
pp. 439-443 ◽  
Author(s):  
Muhd Ridzuan Mansor ◽  
S.M. Sapuan ◽  
Edi Syam Zainudin ◽  
A.A. Nuraini ◽  
Arep Ariff Hambali
Keyword(s):  
Decision Making ◽  
Polymer Composites ◽  
Natural Fiber ◽  
Material Selection ◽  
Selection Process ◽  
Matrix Material ◽  
Final Decision ◽  
Multi Criteria Decision Making ◽  
Hybrid Polymer ◽  
Thermoplastic Matrix

Multi criteria decision making (MDCM) methods are amongst the approaches available in aiding composite designers to make the final decision especially during the material selection process where multiple solutions are present and various requirements are required to be satisfied simultaneously. Thus, in this paper, material selection process of thermoplastic matrix using MDCM methods for hybrid natural fiber/glass fiber polymer composites is presented. The aim is to identify the most suitable type of thermoplastic matrix to be used in the hybrid polymer composites formulation. The Weighted Sum Method (WSM) is applied in the selection process of seven candidate thermoplastic matrix materials based on the product design specifications. The overall analysis highlights that low density polyethylene (LDPE) is the preferred matrix for the intended application based on the highest scores obtained compared to other candidate materials. A signal-to-noise (S/N) ratio analysis was further performed to validate the initial selection results where LDPE once again outperformed other candidate materials with highest S/N ratio score in the non-compensatory approach.

scholarly journals Material selection and design analysis of multi-purpose disposable safety syringe

2018 ◽  
Vol 7 (4.13) ◽  
pp. 214-220
Author(s):  
Mohd Nasri Ishak ◽  
Abd Rahim Abu Talib ◽  
Mohammad Yazdi Harmin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Material Selection ◽  
Selection Process ◽  
Design Analysis ◽  
Element Analysis ◽  
Safety Feature ◽  
The Finite Element Analysis ◽  
Current Design ◽  
Selection For

Current design of safety syringes requires two handed operation and additional processes which is not similar to the normal syringes. Due to this concern, a new design of safety syringe is introduced in order to produce a safety syringe which allows a single-handed operation and similar to the operation of a normal syringes. This paper presents the material selection process and design analysis of a newly devel-oped multi-purpose disposable safety syringe. Based on the design analysis, the force which needed to dismantle the nozzle is found to be 20 N and this value is practical for the end users. The finite element analysis had also shown that the design concept is safe and has safety feature for the user to use. In addition, copolymer is proven as the best material selection for safety syringe production.

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